Introduction

Rod Waterhouse, Pharad

It is well-established that 5G is the next generation wireless network technology that is expected to significantly increase data speeds, produce ultra-low latency times, support the connection of many more devices, and increase energy efficiency of the network elements. To achieve these goals, 5G will need significant contributions and innovations from photonics technologies, whether it be creating the appropriate transport infrastructure with the necessary high capacity, the relevant x-hauling architectures or even utilizing microwave photonics devices and topologies to distribute the wireless signals. Due to the relevance of photonics technology to 5G, we have compiled some relevant and timely articles highlighting where photonics can play a role in 5G. The first article focuses on the role of photonics in the transport of 5G data and data centers as well as how integrated photonics can help resolve some of the challenges facing 5G distribution. The next article discusses the importance of a converged mobile and fixed access network and how it can be implemented. The potential role of LiFi (an optical wireless broadband access technology) is discussed in the next article and how it can be utilized to provide high data mobile communications. Finally, an article discussing analog transport for 5G mobile fronthaul is presented to address the capacity and low-latency requirements for 5G systems while still supporting a centralized architecture. Together, all these articles provide a concise snapshot of the possible exciting roles photonics will play in 5G systems.

Photonics for 5G Networks

Robero Sabella, Ericsson

Photonic technology will play a key role in 5G networks in different contexts. In 5G transport it will allow the transmission and routing of huge amounts of data traffic at an acceptable cost and the transformation of the radio access network. In data center, photonic interconnect and switching will allow the realization of a new architecture able to strongly reduce the energy consumption while providing a high level of flexibility in resource utilization. In future hardware platforms, photonic chip-to-chip interconnect will allow a significant increase of bandwidth density leading to dramatically scaled up global capacity of those platforms. Integrated photonics will be a key technology to realize components and modules at the right costs, while greatly reducing energy consumption and footprint.

Converged fixed-mobile access-metro optical network for 5G with programmable and elastic optical systems and SDN/NFV control

A holistic approach is essential in order to define a converged mobile and fixed access infrastructure, both at structural and functional level, instead of having multiple infrastructures delivering the same or similar services. This converged infrastructure should maximize: i) the benefits of the high-capacity and cost-effective optical access network solutions, addressing not only the transport requirements of fixed subscribers as done so far, but also for 5G mobile x-haul (fronthaul/backhaul) networks, and ii) the SDN/NFV architectural frameworks to address the challenge of jointly managing and operating heterogeneous access and transport networks and distributed cloud infrastructures to offer end-to-end network services and network slice services for fixed and mobile users.

We live in an increasingly connected world where the spectrum for wireless communications must service an exponentially growing demand for wireless data.

The demand for mobile communications is increasing at over 50% per year according to the Cisco Visual Networking Index. Indeed, by 2021 more than half of 17 billion connected devices will be mobile, 65% of the IP traffic will be from mobile devices, 80% of the internet traffic will be video requiring high-speed wireless at an average speed of 20 Mbps. This demand is expected to increase as the Internet of Things (IoT) becomes a reality, and the number of connected devices grows from 5 billion to over 20 billion by 2020. Indeed, in 2017 for the first time, more objects were connected than human beings on Earth, with 8.38 billion connected devices compared to 7.5 billion humans. (source Gartner 2017). Unsurprisingly, in 2016, over 50% of all wireless data went through a Wi-Fi access point. Figure 1 shows the historical and predicted demand for wireless data, pointing clearly to the inevitably growing shortfall in available wireless capacity over the years.

Analog Transport - An Alternative for Mobile Fronthaul?

Christina Lim, Yu Tian and Ampalavanapillai Nirmalathas, Department of Electrical and Electronic Engineering, The University of Melbourne, Australia

As the wireless data traffic shows no signs of slowing down, this creates a significant challenge for the next generation wireless systems with the aggregated data in the fronthaul easily exceeding the practical limits of current CPRI-based mobile fronthaul, making the capacity of the fronthaul as the key bottleneck for the next generation wireless systems. With many alternatives currently being investigated, analog transport for mobile fronthaul emerges as a simple and practical solution to address the capacity and low-latency requirements while supporting a centralized architecture.